Fred T. Valentine

Treatment with Indinavir, Zidovudine, and Lamivudine in Adults with Human Immunodeficiency Virus Infection and Prior Antiretroviral Therapy

BACKGROUND The new protease inhibitors are potent inhibitors of the human immunodeficiency virus (HIV), and in combination with other antiretroviral drugs they may be able to cause profound and sustained suppression of HIV replication. METHODS In this double-blind study, 97 HIV-infected patients who had received zidovudine treatment for at least 6 months and had 50 to 400 CD4 cells per cubic millimeter and at least 20,000 copies of HIV RNA per milliliter were randomly assigned to one of three treatments for up to 52 weeks: 800 mg of indinavir every eight hours; 200 mg of zidovudine every eight hours combined with 150 mg of lamivudine twice daily; or all three drugs. The patients were followed to monitor the occurrence of adverse events and changes in viral load and CD4 cell counts. RESULTS The decrease in HIV RNA over the first 24 weeks was greater in the three-drug group than in the other groups (P<0.001 for each comparison). RNA levels decreased to less than 500 copies per milliliter at week 24 in 28 of 31 patients in the three-drug group (90 percent), 12 of 28 patients in the indinavir group (43 percent), and none of 30 patients in the zidovudine-lamivudine group. The increase in CD4 cell counts over the first 24 weeks was greater in the two groups receiving indinavir than in the zidovudine-lamivudine group (P< or =0.01 for each comparison). The changes in the viral load and the CD4 cell count persisted for up to 52 weeks. All the regimens were generally well tolerated. CONCLUSIONS In most HIV-infected patients with prior antiretroviral therapy, the combination of indinavir, zidovudine, and lamivudine reduces levels of HIV RNA to less than 500 copies per milliliter for as long as one year.

3-Year suppression of HIV viremia with indinavir, zidovudine, and lamivudine

The use of antiretroviral therapy that includes an HIV protease inhibitor has markedly decreased morbidity and mortality in HIV-infected persons (1-3). In addition, antiretroviral combination therapy that includes a protease inhibitor can suppress viral load levels for up to 2 years (4-8). However, the long-term durability and toxicity of these regimens are unknown. We present results after 3 years of follow-up in patients who received three-drug therapy with indinavir, zidovudine, and lamivudine in a previously reported study (4, 5). Methods Study Design The study was originally designed as a randomized, double-blind comparison of three antiretroviral regimens: indinavir (Crixivan, Merck & Co., Inc., West Point, Pennsylvania), 800 mg every 8 hours; zidovudine (Retrovir, Glaxo Wellcome, Research Triangle Park, North Carolina), 200 mg every 8 hours, with lamivudine (Epivir, Glaxo Wellcome), 150 mg every 12 hours; and all three drugs together at the same specified doses (4, 5). Patients were encouraged to drink at least 1.5 L of fluid per day. We report on the patients who were originally assigned to receive three-drug therapy. Institutional review boards at each site approved the study and amendments, and all patients gave informed consent. Study Participants Eligible patients were HIV-infected adults who had received at least 6 months of zidovudine therapy but had never taken lamivudine or an HIV protease inhibitor. Patients had serum viral load levels of at least 20 000 copies/mL (Amplicor HIV Monitor Test, Roche Diagnostic Systems, Branchburg, New Jersey) and CD4 counts between 50 to 400 cells/mm3 at screening. Assessments Patients had study visits at least every 4 weeks through week 52 and every 8 weeks through week 156. At baseline and at each visit, a history was taken, a physical examination was performed, and standardized laboratory tests were conducted without regard to food intake. Serum was processed, stored at 70 C, and subsequently assayed for HIV RNA by using the Amplicor and ultradirect assays (4, 5). T-lymphocyte subgroups were quantified by using flow cytometry. Genotypic analysis of serum HIV RNA was performed as described elsewhere (5). Individual investigators graded adverse events according to standardized guidelines. A drug-related adverse event was one that the investigator assessed as possibly, probably, or definitely related to the study therapy. Nephrolithiasis was defined as the passing of macroscopic stones or gravel or flank pain with or without associated hematuria. During follow-up, investigators assessed lipodystrophy at one time point from October to December 1998 (after approximately 2.5 to 3.5 years of treatment). Patients were considered to have lipodystrophy if they had one or more of the following features without evidence of hypercortisolemia: truncal or central obesity with or without thinning of the extremities; accumulation of body fat in the abdomen, the neck (buffalo hump), the retroperitoneum, the face, or the breasts; and accumulation or redistribution of body fat in some areas that was out of proportion to other body areas. Statistical Analysis Antiretroviral activity was assessed by calculating 1) the proportions (with 95% CIs) of patients whose HIV RNA levels were less than 500 copies/mL (Amplicor assay) and those whose HIV RNA levels were less than 50 copies/mL [ultradirect assay] and 2) the median changes (plus interquartile ranges) from baseline in log10HIV RNA levels (Amplicor assay) and CD4 cell counts over time. Analyses were performed on an intention-to-treat basis. Patients who withdrew early from the study were considered to have had virologic failure at subsequent time points, except for two patients who withdrew for reasons that were not related to therapy and had HIV RNA levels less than 500 copies/mL at the time of withdrawal, as described elsewhere (5). Because the analyses included patients with observed values and those with imputed values, the term contributing patients is used. Among patients with at least two measurements, those who never achieved an HIV RNA level less than 500 copies/mL were considered to have experienced virologic failure. Those who achieved an HIV RNA level less than 500 copies/mL were considered to have experienced virologic failure if they had two consecutive measurements of HIV RNA levels that were at least 500 copies/mL but did not have subsequent re-suppression while receiving the same three-drug regimen. Role of the Study Sponsor Employees of the industry sponsor participated in the study as co-investigators. After designing the study with the input of the other study investigators, these employees implemented the protocol and coordinated data collection and statistical analyses. All investigators interpreted the data, determined the content of the paper, and decided whether to submit the paper for publication. Results Study Participants Originally, 33 patients were randomly assigned to receive three-drug therapy with zidovudine, lamivudine, and indinavir. Median age was 40 years (range, 30 to 62 years). Thirty-one patients (94%) were men, and 2 (6%) were women; 26 (79%) were white, 2 (6%) were African American, 3 (9%) were Latin American, and 2 (6%) were members of other racial or ethnic groups. At study entry, patients had taken zidovudine for a median of 28 months (range, 6 to 92 months) and had a median baseline serum HIV RNA level of 41 900 copies/mL (range, 7550 to 219 040 copies/mL) and a median baseline CD4 count of 133 cells/mm3 (range, 35 to 433 cells/mm3). Of the 33 patients, 12 (36%) discontinued therapy within 3 years: 7 because of increased viral load levels; 2 because of need for contraindicated medications (rifampin and cytotoxic chemotherapy); and 1 each because of nausea, patient request, and investigator recommendation after resolution of urinary tract obstruction. Nine patients experienced virologic failure (6 in the first year, 0 in the second year, and 3 in the third year). Antiretroviral Activity The percentages of contributing patients whose HIV RNA level decreased from baseline to less than 500 copies/mL and less than 50 copies/mL, respectively, were 78% (95% CI, 60% to 90%) and 75% (CI, 56% to 88%) at 1 year, 78% (CI, 60% to 90%) and 66% (CI, 47% to 81%) at 2 years, and 68% (CI, 49% to 83%) (21 of 31 patients) and 65% (CI, 45% to 80%) (20 of 31 patients) at 3 years (Figure 1). Patients experienced a median change in HIV RNA level from baseline of 2.07 log10 copies/mL (interquartile range, 2.39 to 1.61 log10 copies/mL) at 1 year, 2.07 log10 copies/mL (interquartile range, 2.40 to 1.61 log10 copies/mL) at 2 years, and 1.99 log10 copies/mL (interquartile range, 2.32 to 1.31 log10 copies/mL) at 3 years (Figure 2). The median increase in CD4 counts from baseline was 155 cells/mm3 (interquartile range, 95 to 230 cells/mm3) at 1 year, 209 cells/mm3 (interquartile range, 117 to 339 cells/mm3) at 2 years, and 230 cells/mm3 (interquartile range, 150 to 316 cells/mm3) at 3 years (Figure 2). Figure 1. Proportion of patients with serum HIV RNA levels less than 500 copies/mL and less than 50 copies/mL during 3 years of treatment with indinavir, zidovudine, and lamivudine. Figure 2. Median changes in serum HIV RNA level and CD4 cell count from baseline during 3 years of treatment with indinavir, zidovudine, and lamivudine. Genotypic Analysis of Viral Resistance For the nine patients who experienced virologic failure by year 3, results of genotypic analyses performed at baseline and at the time of virologic failure were similar to the results of the 2-year analysis (5). Briefly, six patients had preexisting zidovudine resistance, as evidenced by the presence of the reverse transcriptase T215Y substitution combined with M41L (four patients), K70R (one patient), or D67N/K70R/K219Q (one patient). One patient developed zidovudine resistance (M41L), and all nine developed lamivudine resistance (M184V). Five patients acquired protease substitutions that were previously associated with indinavir resistance (9): M46L/V82A (four patients) and L90M (one patient). In two additional patients, evidence of new protease substitutions (L10V or L63P/S/A) appeared during treatment; however, the significance of substitutions at these two naturally occurring polymorphic sites is unclear. Adverse Events Four patients experienced a serious drug-related adverse event related to nephrolithiasis. Two of these patients experienced urinary tract obstruction, and one withdrew from the study 2 months after the adverse event resolved. Two of these patients also had other serious drug-related adverse events (pain and abdominal pain). In total, 12 of 33 patients (36%) had at least one episode of clinical nephrolithiasis during 3 years of treatment and 7 of 33 patients (21%) had more than one episode. Initial episodes of nephrolithiasis occurred from 24 weeks to 3 years of treatment. A total of 64.6 person-years of follow-up occurred before the first episode of nephrolithiasis or before censoring at 3 years. Therefore, the incidence of nephrolithiasis was 1.86 per 10 person-years of follow-up. Of the 21 patients in active follow-up, 4 (19%) fulfilled the clinical definition of lipodystrophy. When random, nonfasting specimens obtained throughout the study were used, serum triglyceride levels greater than 8.47 mmol/L (750 mg/dL) were documented at least once in 8 of 33 patients (24%) and levels greater than 13.55 mmol/L (1200 mg/dL) were documented in 2 of 33 patients (6%). Serum glucose levels greater than 13.88 mmol/L (250 mg/dL) occurred at least once in 1 of 33 patients (3%). Total serum cholesterol level was measured retrospectively in frozen samples obtained after 0.5, 1, 2, and 3 years of follow-up. Seven of 30 patients (23%) had total serum cholesterol levels of at least 6.21 mmol/L (240 mg/dL), and 1 of 30 patients (3%) had a level of at least 7.76 mmol/L (300 mg/dL) at least once. Discussion Evidence shows that it will be difficult

The Safety, Plasma Pharmacokinetics, and Antiviral Activity of Subcutaneous Enfuvirtide (T-20), a Peptide Inhibitor of gp41-Mediated Virus Fusion, in HIV-Infected Adults

Enfuvirtide (T-20) is a novel antiretroviral agent that blocks HIV-1 cell fusion. A 28-day randomized dose-comparison study was conducted to determine the safety, pharmacokinetics, and antiviral activity of enfuvirtide in 78 HIV-infected adults, most with extensive treatment experience. Patients received enfuvirtide, added to a failing regimen, either by continuous subcutaneous infusion (CSI: 12.5, 25, 50 or 100 mg/day) or by subcutaneous (SC) injection (50 or 100 mg twice daily). Dose-related decreases in viral load were observed, with a maximum mean reduction from baseline of 1.6 log(10) copies/ml (p< 0.001) seen in the 100 mg bid SC group. Most responses diminished by 28 days. Plasma pharmacokinetics and antiviral responses were more consistent for SC injection than for CSI because of technical difficulties experienced with CSI. Injection site reactions were common but generally mild. These results indicate that enfuvirtide is a promising new therapeutic agent for HIV-infected patients, including those with prior antiretroviral treatment.

Evidence of dysregulation of dendritic cells in primary HIV infection

Myeloid and plasmacytoid dendritic cells (DCs) are important mediators of both innate and adaptive immunity against pathogens such as HIV. During the course of HIV infection, blood DC numbers fall substantially. In the present study, we sought to determine how early in HIV infection the reduction occurs and whether the remaining DC subsets maintain functional capacity. We find that both myeloid DC and plasmacytoid DC levels decline very early during acute HIV infection. Despite the initial reduction in numbers, those DCs that remain in circulation retain their function and are able to stimulate allogeneic T-cell responses, and up-regulate maturation markers plus produce cytokines/chemokines in response to stimulation with TLR7/8 agonists. Notably, DCs from HIV-infected subjects produced significantly higher levels of cytokines/chemokines in response to stimulation with TLR7/8 agonists than DCs from uninfected controls. Further examination of gene expression profiles indicated in vivo activation, either directly or indirectly, of DCs during HIV infection. Taken together, our data demonstrate that despite the reduction in circulating DC numbers, those that remain in the blood display hyperfunctionality and implicates a possible role for DCs in promoting chronic immune activation.

A phase II clinical study of the long-term safety and antiviral activity of enfuvirtide-based antiretroviral therapy.

Objectives: The primary objective was to determine the long-term safety of the subcutaneous self-administration of enfuvirtide. Secondary objectives included the determination of enfuvirtide pharmacokinetics and antiviral activity and the immunological response to the enfuvirtide-containing regimen. Methods: A multicenter 48-week uncontrolled open-label rollover study was conducted on 71 HIV-infected adults recruited from previous enfuvirtide clinical trials. Patients with extensive previous use of protease and reverse transcriptase inhibitors received a twice-daily dose of 50 mg enfuvirtide subcutaneously (45 mg deliverable) combined with two or more antiretroviral drugs selected for each individual, guided by resistance testing and previous treatment history. Results: The mean baseline plasma HIV-RNA level was 4.81 log10 copies/ml and the mean CD4 cell count was 134.8 cells/μl. The majority (86.9%) of treatment-emergent adverse events were grade 2 or less in severity. Injection site reactions were common, but no patients discontinued treatment. A mean HIV-RNA change of −1.33 log10 was achieved within 14 days of treatment initiation. At week 48, approximately one-third of all patients in the intent-to-treat population maintained significant suppression of plasma HIV RNA, with either less than 400 copies/ml or more than a 1.0 log10 decline from baseline. The mean gain in absolute CD4 cell counts at 48 weeks was 84.9 cells/μl. Trough plasma concentrations of enfuvirtide were consistently higher than target concentrations. Conclusion: Self-administration of enfuvirtide is not associated with unexpected toxicities for up to one year, and combined with oral antiretroviral drugs was associated with a significant decrease in HIV RNA and an increase in CD4 cell counts.

Residual human immunodeficiency virus (HIV) Type 1 RNA and DNA in lymph nodes and HIV RNA in genital secretions and in cerebrospinal fluid after suppression of viremia for 2 years.

Residual viral replication persists in a significant proportion of human immunodeficiency virus (HIV)-infected patients receiving potent antiretroviral therapy. To determine the source of this virus, levels of HIV RNA and DNA from lymphoid tissues and levels of viral RNA in serum, cerebrospinal fluid (CSF), and genital secretions in 28 patients treated for < or =2.5 years with indinavir, zidovudine, and lamivudine were examined. Both HIV RNA and DNA remained detectable in all lymph nodes. In contrast, HIV RNA was not detected in 20 of 23 genital secretions or in any of 13 CSF samples after 2 years of treatment. HIV envelope sequence data from plasma and lymph nodes from 4 patients demonstrated sequence divergence, which suggests varying degrees of residual viral replication in 3 and absence in 1 patient. In patients receiving potent antiretroviral therapy, the greatest virus burden may continue to be in lymphoid tissues rather than in central nervous system or genitourinary compartments.

Susceptibility of Human Th17 Cells to Human Immunodeficiency Virus and Their Perturbation during Infection

BACKGROUND Identification of the Th17 T cell subset as important mediators of host defense and pathology prompted us to determine their susceptibility to human immunodeficiency virus (HIV) infection. METHODS AND RESULTS We found that a sizeable portion of Th17 cells express HIV coreceptor CCR5 and produce very low levels of CCR5 ligands macrophage inflammatory protein (MIP)-1alpha and MIP-1beta. Accordingly, CCR5(+) Th17 cells were efficiently infected with CCR5-tropic HIV and were depleted during viral replication in vitro. Remarkably, HIV-infected individuals receiving treatment had significantly reduced Th17 cell counts, compared with HIV-uninfected subjects, regardless of viral load or CD4 cell count, whereas treatment-naive subjects had normal levels. However, there was a preferential reduction in CCR5(+) T cells that were also CCR6 positive, which is expressed on all Th17 cells, compared with CCR6(-)CCR5(+) cells, in both treated and untreated HIV-infected subjects. This observation suggests preferential targeting of CCR6(+)CCR5(+) Th17 cells by CCR5-tropic viruses in vivo. Th17 cell levels also inversely correlated with activated CD4(+) T cells in HIV-infected individuals who are receiving treatment. CONCLUSIONS Our findings suggest a complex perturbation of Th17 subsets during the course of HIV disease potentially through both direct viral infection and virus indirect mechanisms, such as immune activation.

Lymphocyte stimulation: transfer of cellular hypersensitivity to antigen in vitro.

Tuberculin-sensitive human lymphocytes cultured for 36 hours with tuberculin elaborate a soluble material which causes nonsensitive lymphocytes to respond to tuberculin in vitro by transformation and proliferation.

Incomplete Immune Reconstitution after Initiation of Highly Active Antiretroviral Therapy in Human Immunodeficiency Virus–Infected Patients with Severe CD4+ Cell Depletion

Immune function was observed for 144 weeks in 643 human immunodeficiency virus (HIV)-infected subjects who (1) had nadir CD4+ cell counts of <50 cells/mm3, followed by a sustained increase to > or =100 cells/mm3 after the initiation of HAART, and (2) were enrolled in a randomized trial of continued azithromycin prophylaxis versus withdrawal for prevention of Mycobacterium avium complex disease. The median CD4+ cell count was 226 cells/mm3 at entry and 358 cells/mm3 at week 144. Anergy (80.2% of patients) and lack of lymphoproliferative response to tetanus toxoid (TT; 73%) after immunization and impaired antibody responses after receipt of hepatitis A (54%) and TT (86%) vaccines were considered to be evidence of impaired immune reconstitution. Receipt of azithromycin did not have an effect on CD4+ cell count but was associated with higher rates of delayed-type hypersensitivity responses to TT (25% of subjects who received azithromycin vs. 15% of those who did not; P=.009) and mumps skin test antigen (29% vs. 17%; P=.001). Although the subjects had only partial responses to immune function testing, the rate of opportunistic infections was very low, and none of the tests was predictive of risk.

Toxicity of Combined Ganciclovir and Zidovudine for Cytomegalovirus Disease Associated with AIDS: An AIDS Clinical Trials Group Study

OBJECTIVE To assess the toxicity, efficacy, and pharmacology of combined zidovudine and ganciclovir therapy in patients with the acquired immunodeficiency syndrome (AIDS) and serious cytomegalovirus (CMV) disease. DESIGN Prospective, phase I multicenter trial (ACTG 004) with patients grouped by previous study drug history. SETTING Three university-based AIDS Clinical Trials Units sponsored by the National Institute of Allergy and Infectious Diseases (NIAID). PATIENTS Forty-one patients with AIDS-related CMV disease. Previous therapy with either zidovudine or ganciclovir was allowed. INTERVENTIONS Patients were treated with zidovudine, 600 to 1200 mg/d; or, if on ganciclovir maintenance, ganciclovir, 5 mg/kg body weight; blood was sampled for pharmacokinetic studies. The other drug was then administered to the patient with blood sampling and, finally, the two drugs in combination were given. Patients were continued on both drug therapies with dose reduction of zidovudine only for grade 3 or 4 toxicity. MEASUREMENTS AND MAIN RESULTS Forty patients were eligible. Hematologic toxicity was frequent, with 9 of the 10 patients requiring dose reductions for grade 3 or 4 toxicity at zidovudine doses of 1200 mg/d. With zidovudine doses of 600 mg/d, 82% experienced such hematologic toxicity. Median survival was 6 months; 10 patients developed intercurrent infection and 19, progressive CMV disease. Pharmacokinetic variables (alpha and beta half-lives, volume of distribution, clearance) were not affected in combination therapy. CONCLUSION The combination of zidovudine and ganciclovir is poorly tolerated in patients with AIDS and serious-CMV disease, with 82% developing severe to life-threatening hematologic toxicity. Such toxicity is not a result of pharmacologic interactions, drug metabolism, or excretion.